This invention relates in general to the manufacture of books and, more particularly, to a machine for separating like signatures from a mixture of signatures.
The typical book, whether it be the traditional hard bound book, a paperback book or a perfect bound magazine, consists of a series of components, known as signatures, which are laid one upon the other in a small stack and are thereafter bound together and contained within a cover. The signatures, which are in effect booklets, represent the product of a printing press, and indeed usually several printing presses are dedicated to a particular book with each run of a press producing at least as many signatures as there are books scheduled for production. The press delivers these signatures in stacks and the stacks are stored until all of the different signatures required for the entire book are available.
When the full complement of signatures is available, the signatures are delivered to a binding machine which assembles them in the proper order--that is collates them--to produce a short stack which is eventually bound together. The collating and binding occurs in a perfect binding machine, which typically include a conveyor chain having so-called chain spaces and a succession of feeders over the chain. Each feeder holds like signatures, but the signatures of course differ from feeder to feeder. As the conveyor chain moves below the feeders, the feeders deposit signatures in the chain spaces that exist along it, thus building up within each chain space a short stack of signatures arranged in the proper order.
Sometimes a feeder will jam or otherwise fail to deliver a signature to a chain space, and as a result the stack which forms in that chain space is incomplete. A counting device on the binding machine detects the incomplete stack or book and rejects it before the signatures within it can be bound together.
While a press run normally produces signatures in excess of the number of books required, the excess often does not compensate for the number lost as incomplete books rejected by the perfect binding machine. As a result, the incomplete stacks so rejected are disassembled--or decollated--and the individual signatures so derived are again reintroduced into the appropriate feeders of the binding machine to be assembled into complete books.
Presently, printing companies decollate incomplete books with manual labor, but that is a time-consuming and expensive procedure, requiring individuals to visually inspect each signature of every incomplete book and place that signature on a stack of like signatures. The machine of the present invention automatically separates the signatures of the incomplete books, one from another, and with a camera captures an image of each. The machine includes a computer which compares each captured image with images stored in its memory, and if it identifies a captured image with one of the stored images, it directs the signature having the identified image to a station where like signatures possessing that image are collected.